bitget function is not invoking output bits in a vector

k=k+1; %% k is counter and its chainging even more than (length(A))
for t = 1:1:length(A)    %% A is a vector contains 8 elements 
      recovered_bits(1,k)= bitget(A(1,t),1);   % extract LSB of each element in array and put them (LSB) in recovered_bits vector
      k=k+1;  
end 
%% Output ----> recovered_bits = [] knowing that i trying to preallocate the vector previously 

[KALYAN ACHARJYA]

What is A here?

[madhan ravi]

See PREALLOCATION it improves code efficiency

[Anmar Mohammed]

A is a vector contain 8 pixels consider it double

Answer 1

[madhan ravi]

You don't need a counter for this case , please pre-allocate before loop!

recovered_bits=cell(1,length(A)); %proper pre-allocation
for t = 1:length(A)    
      recovered_bits{t}= bitget(A(1,t),1);  
end 
[recovered_bits{:}]

[Anmar Mohammed]

Thanks for sharing, it really helped, the k is needed simply because the code above is invoked in a bigger problem within functions, thank you all for helping me, greetings.

[madhan ravi]

Anytime :), see Steven Lords answer which is the efficient way to do what you are doing

Answer 2

[Steven Lord]

Why loop?

r = randi([0 intmax('int8')], 8, 1, 'int8');
recovered_bits = bitget(r, 1);
result = [r, recovered_bits, mod(r, 2)]

The second and third columns of result should be the same.

[Anmar Mohammed]

hi, am working on image steganography.. i used loop because i needed the first LSB or i may need the second or the third LSBs.. the output depend on other parameters with entire recieved image.. your code is intersting i tried to have the fist 3 LSBs using your modified code but an error ocured concerning input size, any suggestions are much preciated, thanks in advance.

r = randi([0 intmax('uint8')], 8, 1, 'uint8');
recovered_bits = bitget(r, 1:3,'uint8');
result = [r, recovered_bits]

Error using bitget
Inputs must have the same size.

Answer 3

[KALYAN ACHARJYA]

Initiallize k=1, otherwise K is not defined

k=1; %% k is counter and its chainging even more than (length(A))
for t = 1:1:length(A)    %% A is a vector contains 8 elements 
      recovered_bits(1,k)= bitget(A(1,t),1);   % extract LSB of each element in array and put them (LSB) in recovered_bits vector
      k=k+1;  
end 

[KALYAN ACHARJYA]

For example I have choosen different A

A=[4 6 7 4 3 0 8 4];
for t=1:1:length(A)    %% A is a vector contains 8 elements 
    recovered_bits(t)=bitget(A(1,t),1);  % extract LSB of each element in array and put them (LSB) in recovered_bits vector 
end 
%% Output ----> recovered_bits = [] knowing that i trying to preallocate the vector previously
disp(recovered_bits);

[Anmar Mohammed]

Oh.. am sorry it's already initialized and its K=1 not K=k+1 as wrote above, my bad.